Backlight module of illuminated keyboard

Abstract

A backlight module of an illuminated keyboard includes: a circuit board including a first circuit, a second circuit, a gathering portion and a conduction portion, and the first circuit having a first line section; a light guiding plate disposed on the circuit board, including a first light guiding region and a second light guiding region, and the first light guiding region disposed on the first line section; a plurality of light-emitting elements disposed in parallel on the first line section; and an resistor unit including a first resistor and a second resistor, the first resistor disposed on the first circuit, and the second resistor disposed on the second circuit. A sum of a line impedance of the first circuit and an impedance of the first resistor is substantially equal to a sum of a line impedance of the second circuit and an impedance of the second resistor.

What is claimed is: 
     
       1. A backlight module of an illuminated keyboard, the backlight module comprising:
 a circuit board, comprising a first circuit, a second circuit, a gathering portion and a conduction portion, the first circuit and the second circuit electrically connected to the gathering portion, the gathering portion electrically connected to the conduction portion, the first circuit comprising a first line section, and the second circuit comprising a second line section; 
 a light guiding plate, disposed on the circuit board, comprising a first light guiding region and a second light guiding region, the first light guiding region disposed on the first line section, and the second light guiding region disposed on the second line section; 
 a plurality of light emitting elements, disposed in parallel on the first line section and disposed in parallel on the second line section; and 
 a resistor unit, comprising a first resistor and a second resistor, the first resistor disposed on the first circuit, and the second resistor disposed on the second circuit, 
 wherein a sum of a line impedance of the first circuit and an impedance of the first resistor is substantially equal to a sum of a line impedance of the second circuit and an impedance of the second resistor. 
 
     
     
       2. The backlight module according to  claim 1 , wherein the first light guiding region comprises a first sub-region and a second sub-region disposed adjacently, the first sub-region comprises a first single key light guiding region and a second single key light guiding region disposed on two sides thereof, and one of the light emitting elements is disposed on one side of the first single key light guiding region and emits a light toward the first single key light guiding region and the second single key light guiding region. 
     
     
       3. The backlight module according to  claim 2 , wherein the first sub-region comprises a light transmitting channel passing through the first single key light guiding region and the second single key light guiding region. 
     
     
       4. The backlight module according to  claim 3 , wherein the first sub-region is disposed adjacent to a side of the light guiding plate, a distance between the first single key light guiding region and the side is greater than a distance between the second single key light guiding region and the side, and a microstructure density of the first single key light guiding region is less than a microstructure density of the second single key light guiding region. 
     
     
       5. The backlight module according to  claim 2 , wherein the light guiding plate comprises a third light guiding region, the third light guiding region comprises a third single key light guiding region, an area of the third single key light guiding region is greater than an area of the first single key light guiding region or an area of the second single key light guiding region, and the gathering portion is disposed on the circuit board in a region vertically corresponding to the third light guiding region. 
     
     
       6. The backlight module according to  claim 1 , wherein an amount of the light emitting elements on the first line section is equal to an amount of the light emitting elements on the second line section, a line length of a center position of the light emitting elements on the first circuit to the gathering portion is greater than a line length of a center position of the light emitting elements on the second circuit to the gathering portion, and the impedance of the first resistor is less than the impedance of the second resistor. 
     
     
       7. The backlight module according to  claim 1 , wherein the first light guiding region comprises a plurality of single key light guiding regions, the second light guiding region comprises a plurality of single key light guiding regions, a first ratio of a microstructure area sum of the single key light guiding regions of the first light guiding region divided by an amount of the light emitting elements on the first line section is greater than a second ratio of a microstructure area sum of the single key light guiding regions of the second light guiding region divided by an amount of the light emitting elements on the second line section, and the impedance of the first resistor is greater than the impedance of the second resistor. 
     
     
       8. The backlight module according to  claim 1 , wherein an amount of the light emitting elements on the first line section is less than an amount of the light emitting elements on the second line section, a line length of a center position of the light emitting elements on the first circuit to the gathering portion is about equal to a line length of a center position of the light emitting elements on the second circuit to the gathering portion, and the impedance of the first resistor is greater than the impedance of the second resistor. 
     
     
       9. The backlight module according to  claim 1 , wherein an amount of the light emitting elements on the first line section is equal to an amount of the light emitting elements on the second line section, the first light guiding region comprises a plurality of single key light guiding regions, the second light guiding region comprises a plurality of single key light guiding regions, a microstructure area sum of the single key light guiding regions in the first light guiding region is greater than a microstructure area sum of the single key light guiding regions in the second light guiding region, and the impedance of the first resistor is greater than the impedance of the second resistor. 
     
     
       10. The backlight module according to  claim 1 , wherein the first resistor and the second resistor are electrically connected with the gathering portion. 
     
     
       11. The backlight module according to  claim 1 , wherein the conduction portion is disposed adjacent to a long side of the circuit board, and the gathering portion is disposed adjacent to the conduction portion. 
     
     
       12. A backlight module of an illuminated keyboard, the backlight module comprising:
 a circuit board, comprising a first circuit, a second circuit, a gathering portion and a conduction portion, the first circuit and the second circuit electrically connected to the gathering portion, and the gathering portion electrically connected to the conduction portion; 
 a light guiding plate, disposed on the circuit board, comprising a first light guiding region and a second light guiding region; 
 a plurality of first light emitting elements, disposed in parallel on the first circuit, and located in the first light guiding region; and 
 a plurality of second light emitting elements, disposed in parallel on the second circuit, and located in the second light guiding region, 
 wherein a total impedance of the first circuit is substantially equal to a total impedance of the second circuit. 
 
     
     
       13. The backlight module according to  claim 12 , whereon the first circuit comprises a first line section located under the first light guiding region, the second circuit comprises a second line section located under the second light guiding region, the first light emitting elements are disposed in parallel on the first line section, and the second light emitting elements are disposed in parallel on the second line section. 
     
     
       14. The backlight module according to  claim 13 , further comprising:
 a resistor unit, comprising a first resistor and a second resistor, the first resistor disposed on the first circuit, and the second resistor disposed on the second circuit, 
 wherein a sum of a line impedance of the first circuit and an impedance of the first resistor is substantially equal to a sum of a line impedance of the second circuit and an impedance of the second resistor. 
 
     
     
       15. The backlight module according to  claim 14 , wherein an amount of the first light emitting elements on the first line section is equal to an amount of the second light emitting elements on the second line section, a line length of a center position of the first light emitting elements on the first circuit to the gathering portion is greater than a line length of a center position of the second light emitting elements on the second circuit to the gathering portion, and the impedance of the first resistor is less than the impedance of the second resistor. 
     
     
       16. The backlight module according to  claim 14 , wherein an amount of the first light emitting elements on the first line section is equal to an amount of the second light emitting elements on the second line section, the first light guiding region comprises a plurality of single key light guiding regions, the second light guiding region comprises a plurality of single key light guiding regions, a microstructure area sum of the single key light guiding regions in the first light guiding region is greater than a microstructure area sum of the single key light guiding regions in the second light guiding region, and the impedance of the first resistor is greater than the impedance of the second resistor. 
     
     
       17. The backlight module according to  claim 13 , wherein an amount of the first light emitting elements on the first line section is less than an amount of the second light emitting elements on the second line section, a line length of a center position of the first light emitting elements on the first circuit to the gathering portion is about equal to a line length of a center position of the second light emitting elements on the second circuit to the gathering portion, and the impedance of the first resistor is greater than the impedance of the second resistor. 
     
     
       18. The backlight module according to  claim 12 , wherein the first light guiding region comprises a first sub-region and a second sub-region disposed adjacently, the first sub-region comprises a first single key light guiding region and a second single key light guiding region disposed on two sides thereof, and one of the first light emitting elements is disposed on one side of the first single key light guiding region and emits a light toward the first single key light guiding region and the second single key light guiding region. 
     
     
       19. The backlight module according to  claim 18 , wherein the light guiding plate comprises a third light guiding region, the third light guiding region comprises a third single key light guiding region, an area of the third single key light guiding region is greater than an area of the first single key light guiding region or an area of the second single key light guiding region, and the gathering portion is disposed on the circuit board in a region vertically corresponding to the third light guiding region. 
     
     
       20. The backlight module according to  claim 12 , wherein the conduction portion is disposed adjacent to a long side of the circuit board, and the gathering portion is disposed adjacent to the conduction portion.